1. Field
The present disclosure relates generally to inspecting objects and, in particular, to the nondestructive inspection of objects. Still more particularly, the present disclosure relates to a method and apparatus for performing nondestructive inspections of an object using a flexible ultrasound inspection system.
2. Background
Nondestructive inspection involves evaluating an object without causing damage to the object. This type of inspection may include evaluating properties of the object without causing permanent changes. These inspections may be used to identify undesirable and desirable properties.
For example, nondestructive inspection may be used to identify inconsistencies in composite parts. These inconsistencies may include, for example, voids, delaminations, disbonding, and other features that may cause the composite part to perform at a level that is less than desired.
Nondestructive inspection techniques may include, for example, ultrasound testing, remote visual inspection, eddy current testing, x-ray testing, and other suitable types of techniques. With ultrasound testing, an ultrasound transducer is typically coupled to a test object. The coupling may be performed using a couplet such as oil, water, or other types of couplets.
The ultrasound transducer is configured to send sound signals into the test object. Response sound signals are detected by the same transducer or a different transducer. The response sound signals may be reflections of some of the sound signals sent by the transducer and may come from an interface such as the back wall of a test object or an inconsistency in the test object. The response sound signals may be displayed or otherwise analyzed to determine whether undesired inconsistencies are present in the test object.
An ultrasound inspection system with a single transducer may be used to inspect the entire surface of the test object. With a single transducer, that transducer is moved over the surface of the test object that is being inspected. This process, however, may take more time than desired.
When testing objects with large surface areas, transducer arrays with multiple transducers may be used to provide greater coverage as compared to using a single transducer. With an array of transducers, the array itself is moved and sound signals may be sent into the test object in a larger area as compared to a single transducer. In this manner, a transducer array may be used to perform an inspection of an object more quickly than a single transducer is able to perform the same inspection.
Although using transducer arrays may reduce the amount of time needed to inspect test objects, when non-planar surfaces are present, the ability of a transducer array to generate desired response sound signals may be reduced. For example, transducer arrays are typically connected to a rigid frame. If a surface is non-planar, some of the transducers in the transducer array may not have a desired coupling to the surface of the object. If the transducers in the transducer array are not coupled to the surface properly, the response sound signals may not accurately reflect properties in the test object.
In some cases, the transducer array frame may have segments that are moveable relative to each other. Transducers on the different segments may then be repositioned to more closely conform to the shape of the surface of the test object.
Even with these positionable segments, the transducers ability to conform to curves of some test objects may be infeasible. As a result, the use of a smaller sized transducer array or a single transducer may then be used to test these sections of the test object with curved surfaces that are too great for the array. This type of inspection, however, may take more time and effort than desired. Therefore, it would be desirable to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.